Impact of Overhang Construction on Girder Design 5. Report Date November 2009; Revised May 2010 The girders are typically uniformly spaced transversely with the deck extending past the fascia girders, thereby resulting in an overhang. While designers commonly employ rules of thumb with regard to the geometry of the overhang, these
Design Step 4 Design of Deck Prestressed Concrete Bridge Design Example Task Order DTFH61-02-T-63032 4-2 dead and live loads acting on the deck. The deck overhang region is required to be designed to have a resistance larger than the actual resistance of the concrete parapet SA13.4.2 . Design Step
Using the railing capacity to design the deck overhang reinforcing can be overly conservative. The IDM now allows the use of 1.25 x F t as a maximum.
LRFD DESIGN EXAMPLE: PRESTRESSED PRECAST CONCRETE BEAM BRIDGE DESIGN Table of Contents Cover Section 1: Project Information 1.01 About this Design Example 2.06 Traditional Deck Design 2.07 Deck Overhang Design 2.08 Creep and Shrinkage Parameters 2.09 Expansion Joint Design 2.10 Composite Neoprene Bearing Pad Design
I'm currently designing a deck overhang with a TL-4 barrier using AASHTO LRFD. For Design Case 1 Extreme Event Limit State , the overhang must be designed for the vehicular collision plus dead load moment acting concurrently with the axial tension from verhicular collision force.
This design example uses the riae lasi Med Equivalent Strip Method , in which the deck is divided into transverse strips, assumed to be supported on rigid supports at the center of the girders.
design example includes detailed design computations for the following bridge features: conc rete deck, steel plate girder, bolted field splice, shear connectors, bearing stiffeners, welded connections, elastomeric bearing, cantilever abutment and
Design Step 2.12 - Design for Flexure in Deck Overhang Bridge deck overhangs must be designed to satisfy three different design cases. In the first design case, the overhang must be designed for horizontal transverse and longitudinal vehicular collision forces.
parapets, in conjunction with the deck overhang designs, are rated for Crash Test Level TL4 - and TL-5, respectively, which is adequate for most situations. Design Guides 3.2.1 - LRFD Deck Design Page 3.2.1-2 April 2012 LRFD Deck Slab Design Example: 7 ft. Beam Spacing, Positive Moment .
For Design Case 1, the deck overhang supporting concrete parapet railings shall be designed to resist the combined effects of tensile force T and moment M s , and other applicable forces at the inside face of the parapet or the gutter line, as specified as follows.
deck overhang will be designed for the dead load and live load that occupy the overhang. For design case 3, application of design vehicular live load shall be in accordance with provision .4 of the LRFD Specifications .
2.08 Deck Overhang Design 2.07 Traditional Deck Design 2.06 Empirical Deck Design 2.05 Prestressed Beam Design - Part II 2.04 Prestressed Beam Design - Part I 2.03 Live Load Analysis LRFD Design Example Table of Contents i. Two simple spans 90'-0" each, 30 degree skew. Minor horizontal curvature Multi-column pier on prestressed concrete piles.
The example illustrates the design of a typical three-span continuous straight steel I-girder bridge with spans of 140-0 175-0 140-0. Specifically, the example illustrates the design of selected critical sections from an exterior girder at the
bridges, presenting deck types such as concrete deck slabs, metal grid decks, orthotropic steel decks, wood decks, and several others. The choice of the particular deck type to use can depend on several factors, which may include the specific application,
The example illustrates bridge deck design in accordance with the AASHTO LRFD Bridge Design Specifications AASHTO, the deck overhang has to be designed to meet the requirements for Extreme Event II. The AASHTO 2012 requires bridge deck overhangs to be Chapter 10 Concrete Decks 10-6 10.4 DESIGN CONSIDERATIONS
.1-2.1 Type F Barrier Design Example LRFD BRIDGE DESIGN 13-17 This example illustrates a design check of the vertical reinforcing steel that ties a standard Mn/DOT Type F barrier to a concrete deck. reproduced from LRFD Figure CA13.1-1.